[Unjucky]

May Allah guide him for this is nothing but misguidance from his part. Both groups of Qadiyani's are the same for all intents and purposes- they are KUFFAR. The Lahori Qadiyani's, whilst claiming that they do not believe Mirza claimed Prophethood (although I personally believe this to be some sort of taqiyyah to avoid persecution in Pakistan) are still kuffar for not making takfeer of Mirza or the 'normal' Qadiyani's etc. And their blatant rejection of well known aspects of Islam such as jihad, etc.

Regarding the Lahori Muhammad Ali, I doubt Deedat would need to rely on his works since refutations of Christianity have been around for centuries- many Muslims studied and refuted the Bible including the likes of Ibn Taymiyyah. Not to mention Christian works regarding things like textual criticism, higher criticism etc have been around for centuries also so refutations of Christianity is nothing new